Page 502 - Practical English Usage 3ed - Michael Swan, Oxford

question tags (l): basic information 487
Negatives are usually contracted. Full forms are possible in formal speech.
That's the postman, isn't it? You take sugar in tea, don't you?
They promised to repay us within six months, did they not? (formal) Question tags can be used to check whether something is true, or to ask for agreement.
2 negative after affirmative, and vice versa
Question tags are used after affirmative and negative sentences, but not after questions.
You're the new secretary, aren't you?
You're not the new secretary, are you?
(BUT NOT l~re}'6u the new secretary, aren't }'6!t?)
To check information or ask for agreement, we most often put negative tags after affirmative sentences, and non-negative tags after negative sentences.
1+ -I 1- +1 It's cold, isn't it? It's not warm, is it?
For 'same-way' tags, see 488.7
3 auxiliaries
If the main sentence has an auxiliary verb (or non-auxiliary be), this is repeated in the question tag.
"I
Sally can speak French, can't she?
"I
The meeting's at ten, isn't it?
~
You didn't speak to Luke, did you?
~I
You wouldn't like a puppy, would you?
If the main sentence has no auxiliary, the question tag has do. "I
"I
Harry galle you a cheque, didn't he?
4 negative words
Non-negative tags are used after sentences containing negative words like neller, no, nobody, hardly, scarcely and little.
You like oysters, don't you?
You neller say what you're thinking, do you? (NOT ••• tkm't}'6u?) ' d''1'( . "2\
/tsnogoo,ISIt. NOT•••tmt
It's hardly rained at all this summer, has it? There's little we can do about it, is there?
Jt~J
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